COMPTIA A+

Summary for exams

alexandria gangiah . .
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CHAPTER ONE
SAFETY AND PROFESSIONALISM
TOOLS OF THE TRADE

HARDWARE TOOLS
 1. Nut driver and No2 Philips screwdriver:
it’s best to have numerous screwdrivers or a bit-driver and multiple bits on
hand to accommodate any type of nut or screw.For the vast majority of PC
builds and upgrades, a basic No. 2 Phillips screwdriver will be the only tool
you’ll need. As you start working with more diverse hardware and
Page | 2 accessories, or if you delve into the warranty-voiding world of PC
modifications, you’ll need different-size screwdrivers and nut drivers.

I keep an array of screwdrivers on hand, as well as a bit-driver and an

assortment of magnetic bits. I also like to have a small electronics toolkit
handy, on the off chance that I’ll need to disassemble a drive or other
accessory that’s held together with a less-common type of screw. Most
small electronics toolkits will feature Allen (hex), Torx, Phillips, and flat-
head bits. Another screw type that’s becoming more common is the five-
pointed Pentalobe, which is used on some Samsung SSDs and mobile
devices.

2. Hemostats and tweezers:

Used to pick up and hold small items, clamp parts together for gluing, or
as a handy heat sink when soldering.

3. IC inserter:
IC Inserter Integrated circuits are chips that are integrated with the
construction of electronic hardware for its ability to be easily replaced if
damage to the chip manifest. To insert the new chip carrier, PI
Manufacturing provides the reverse action IC inserter.

4. Spudger and Pry bar:

Pry bars are plastic. Both objects are the lifting, opening and prying tool
for cell phone and electronics repair. A spudger is a tool that is used to
assist with opening, prying, installing and removing components from
objects such as electronics. A spudger is manufactured with various
metals including stainless steel, fibre glass nylon materials and plastics.

5. Multimeter in a PC (Volt/ohm meter)

One of the most basic pieces of electronic troubleshooting equipment is
the Multimeter. These test instruments are available in both analogue and
digital readout form and can be used to directly measure electrical values
of voltage (V), current in milliamperes (mA) or amperes (A), and resistance
in ohms. Therefore, these devices are referred to as VOMs (volt-ohm-
milliammeters) for analogue types, or DMMs (digital Multimeter) for digital
types.

Figure 3.2 depicts a digital Multimeter. With a little finesse, you can use
this device to check diodes, transistors, capacitors, motor windings, relays,
and coils. This particular DMM contains facilities built into the meter to test
transistors and diodes. These facilities are in addition to its standard
functions of current, voltage, and resistance measurement; however, in
computer repair work, only the voltage and resistance functions are used
extensively.
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figure 3.2 digital Multimeter

DC voltage
check

6. Cable testers
The most frequent hardware-related cause of network problems involves
bad cabling and connectors. Several specialized, handheld devices
designed for testing the various types of data communication cabling are
available.

7. POST Cards
A POST card is a diagnostic device that plugs into the system's expansion
slot and tests the operation of the system as it boots up. These cards can
be as simple as interrupt and direct memory access (DMA) channel
monitors, or as complex as full-fledged ROM BIOS diagnostic packages
 that carry out extensive tests on the system.

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POST card

8. Thumb drivers
Types to carry
- Anti-malware drive- used as anti-virus to clean up a system
- Used to store software

TROUBLESHOOTING THEORY
Two factors make for successful troubleshooting: extensive computer knowledge
and an understanding of human psychology. You must understand how hardware
and software work to troubleshoot them. You also must treat customers with
 respect. By combining these two factors, you can quickly detect and solve
computer problems.
To become a successful trouble-shooter, you need to
• Learn as much as possible during the client interview
Page | 5 • Evaluate the client’s environment
• Use testing and reporting software to gather information about the system
• Form a hypothesis (a theory you will try to prove or disprove)
• Use the troubleshooting cycle and the CompTIA six-step troubleshooting
process to isolate and solve the problem, to wit:

1 Identify the problem

2 Establish a theory of probable cause (and question the obvious)
3 Test the theory to determine the cause
4 Establish a plan of action to resolve the problem and implement the solution
5 Verify full system functionality and, if applicable, implement preventative
measures
6 Document findings, actions and outcomes

It is necessary to approach computer problems from a logical standpoint. To best

accomplish this, PC technicians will implement a troubleshooting methodology
(or maybe more than one).

As you attempt to troubleshoot computer issues, think in terms of that six-step

process. Plug the problem directly into these steps.

For example, in Step 1 you might identify an issue; maybe the computer won’t
turn on. For Step 2, a possible theory could be that the computer is not plugged
in to the AC outlet. To test the theory in Step 3, you would plug the computer in.
If it works, then great, but if it doesn’t, you would go back to Step 2 and establish
a new theory. When you have reached a theory that tests positive, move on to
Step 4 and establish the plan of action based on that theory, and then implement
your solution. (Keep in mind that many plans of action will be more complicated
than just plugging the computer in! Perhaps the AC outlet was loose, which
would require a licensed electrician to fix it.) Next, in Step 5 you want to test.
Always test and verify that the system is functioning correctly. If need be,
implement preventative measures; for example, re-route the power cable so that
it is out of the way and can’t be disconnected easily. Finally, in Step 6, you want
to document your findings and the outcome. In many companies, documentation
begins right when you first get a troubleshooting call (or trouble ticket), and the
 documentation continues throughout the entire process. You can track
documentation on paper, or in an online system; it depends on your company’s
procedures. Be sure to keep track of what happened, why it happened, and how
you fixed the problem.
Because computer failures happen to the customer (who usually is less
Page | 6 technically aware than you of the possible causes for the problem), you must
work with the customer to create a complete list of symptoms so that you can
find the right solution quickly and accurately. To do this, you need to
• Carefully observe the customer’s environment to look for potential causes of
computer problems, such as interference sources, power problems, and user
error.
• Ask the customer what (if anything) has changed recently about the
computer or its environment. Anything from new hardware or software being
installed, new telephone or network being installed, or even a new coffee maker
or air-conditioning unit could be at the root of the problem. A simple way to ask
this would be to say, “What has changed since the last time it (the PC) worked?”
• Determine what tasks the customer was performing on the PC. You can
determine this not only by asking the customer questions, but by reviewing
system log files, browser history, and so on
• Ask the customer detailed questions about the symptoms, including unusual
system behaviour, such as noises or beeps, office events taking place around the
same time, onscreen error messages, and so on.
Because some types of computer problems aren’t easy to replicate away from
the customer site, your customer might see system problems you never will,
even if you attempt to reproduce the problem.
Remember, troubleshooting is the art and science of quickly and accurately
determining what is wrong with a customer’s system. Troubleshooting is an art
because every technician will bring his or her own experience and personality to
the task. Troubleshooting is also a science because you can apply a definite
method that will bring you a great degree of success.
Note: Windows generates several log files during routine use that can be useful
for determining what went wrong. Many of these can be viewed through the
Event Viewer. To view the contents of the Event Viewer, right-click Computer/My
Computer, click Manage and click Event Viewer. The Event Viewer captures three
types of information: Application errors, security audits, and system errors.
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CHAPTER 2
THE VISIBLE COMPUTER
PRIMARY PC COMPONENTS
 PRIMARY PC COMPONENTS
 The system unit
Page | 8 A system unit is the part of a computer that houses the primary
devices that perform operations and produce results for complex
calculations. It includes the motherboard, CPU, RAM and other
components, as well as the case in which these devices are housed.
This unit performs most of the functions that a computer is required
to do.

 The monitor
A monitor is a piece of computer hardware that displays the video
and graphics information generated by a connected computer
through the computer's video card.

 The keyboard and mouse

A computer keyboard allows an operator to give commands to the
computer in a simple way by pressing keys. The keys on a keyboard
are typically labelled with their input function, ranging from letters
of the alphabet to numbers and symbols. There is no one standard
keyboard; all keyboard or computer manufacturers create their own.

A computer mouse is a handheld hardware input device that

controls a cursor in a GUI and can move and select text, icons, files,
and folders. For desktop computers, the mouse is placed on a flat
surface such as a mouse pad or a desk and is placed in front of your
computer.

 A printer
Printer is one of the computer's output device, used to print
computer processing results in the relevant media. A printer is a
device that accepts text and graphic as output from a computer and
transfers the information to standard size sheets of paper. It may
vary. in size, speed, and cost.

 Speakers
 Game controller
 Web cam
 Headset
 Microphone
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EXTERNAL CONNECTIONS

INSIDE THE PC
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WHAT IS A COMPUTER?
an electronic device for storing and processing data, typically in binary form,
according to instructions given to it in a variable program.
 CHAPTER 3
CPU
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CENTRAL PROCESSING UNIT

WHAT IS A CPU?
central processing unit of the computer. A computer's CPU handles all
instructions it receives from hardware and software running on the computer.
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SPEEDS AND CORES OF CPU